1. Field of the Invention
This invention relates to a method of treating a solution comprising ions of gold and cyanide and more particularly, to a method of purifying the solution by treating it with metallic gold which precipitates metallic silver therefrom if silver ions are present therein.
2. Discussion of the Prior Art
It is known that small amounts of metallic impurities on gold plated surfaces lead to thermocompression bonds thereto which are defective. It appears that the chief culprit is metallic silver impurities on the gold plated surface. In this regard, reference is made to Physical Electronics Industries, Inc., APPLICATIONS NOTE, No. 7310 (3-23-73), entitled "Plating Analysis: TO-5 Headers." A method for preventing the electrodeposition of metallic silver from gold electroplating solutions is therefore needed and is desired.